Experimental Setup

• Beam.
  • Energies 6.5 GeV (17 PAC days), 8.6 GeV(15 PAC days), and 10.7 GeV (15 PAC days).
  • Beam pipe size: Medium.
  • Polarized for 3 and 5 pass.
• HMS
  • Standard configuration for electrons/positrons.
  • Momentum range: 1.5 to 5.3 GeV.
  • Angle range: 13.5 to 49 degrees.
• SHMS.
  • Momentum range: 1.6 to 6 GeV.
  • Angle range: 7.1 to 20 degrees.
  • Detectors:
  • Noble gas with standard gas (pion threshold 7 GeV: 40% neon, 60% argon)
  • Heavy gas (1 atmosphere C4F10 (?) for pion threshold of 2.6 GeV)
  • Aerogel with index 1.015 (kaon threshold 2.85 GeV). Elog entry
  • standard scintillators, drift chambers, and calorimeter.
• Triggers
  • Coincidence of HMS 3/4 and SHMS 3/4
  • Coincidence of HMS EL_REAL and SHMS 3/4
  • HMS 3/4 (SHMS read out even if no trigger)
  • HMS EL_real (ditto)
  • HMS EL_real only (no SHMS readout)
  • HMS 3/4 only (no SHMS readout)
  • SHMS 3/4 (for cosmics)